2 ms·
> The PSRAM/HyperRAM PIO engine provides 42/32 MB/s (write/read) of memory bandwidth. Further, four PIO engines are used to provide four seperate read/write mem
by sitkack 2y ago
> The PSRAM/HyperRAM PIO engine provides 42/32 MB/s (write/read) of memory bandwidth. Further, four PIO engines are used to provide four seperate read/write memory ports. This allows independent memory access for the emulated CPU, video DMA, and receive/send Ethernet traffic. Note that all 32 instruction slots are used.
> The video PIO engine can support up to a sysclk/2 pixel rate. Thus, for the 300 MHz sysclk typically used, it is possible to run 1080p60 at a pixel rate of 148.5 MHz. The default video rate is 1024 x 768 @ 70Hz, as this matches the screen used for development and the pixel rate is an integral divisor from sysclk. Only five PIO instruction slots are used.
PIO code https://github.com/rscott2049/DECstation2040/blob/main/sw/psram/libhyperram/hyperram.pio https://github.com/rscott2049/DECstation2040/blob/main/sw/ps...
Amazing